Embodiments of the inventive concepts relate to a silicon photonics technology, and in particular, to an optical coupling technology.
A grating coupler and a mode size converter are widely used to realize an optical coupling with a silicon photonics integrated circuit. Especially, the use of the mode size converter can provide technical advantages, such as higher optical coupling efficiency (e.g., less than 1 dB) and wavelength-independent optical coupling and decoupling.
However, for the optical coupling technologies, an edge coupling is needed to use the mode size converter. For example, there has been a technical difficulty in realizing a vertical coupling in wafer level. In addition, it is necessary to perform an additional process of polishing a facet of a final silicon photonics chip.